Packaged semiconductors can be embodied as single die packages or multi-chip packages. On example of single chip packages is a chip scale package (CSP).
Multichip packages include multichip modules (MCM) and System-in-a-Package or System in Package (SIP). As commonly used and defined herein, a plurality of die mounted on the same plane (e.g. the cavity substrate) is referred to as a MCM, whereas vertically stacked die stacking is referred to as a SIP.
The MCM or SIP performs all or most of the functions of an electronic system, such as the functions required by a cellular phone or music player. An exemplary SIP generally comprises several chips, such as a specialized processor, dynamic random access memory (DRAM), flash memory, and passive components, such as resistors, capacitors and in some case inductors, all mounted on the same substrate (e.g. a multi-layer printed circuit board (PCB)). This means that a complete functional unit can be built in a single multi-chip package, so that few external components are needed for system operation.
In certain applications, packaged semiconductors need high value capacitors, such as for power supply decoupling to minimize switching noise in certain electronic systems. To realize such high value capacitors, conventionally, an embedded capacitor is used. Conventional embedded capacitors are realized using a stack up structure comprising a plurality of stacked metal layers having dielectric layers therebetween and via connections between the metal layers formed on a conventional multi-layer PCB substrate, such as FR4 or BT.